clear
clc
c=[66.8,75.6,87,58.6,57.2,66,66.4,53,78,67.8,84.6,59.4,70,74.2,69.6,57.2,67.4,71,83.8,62.4];
intcon=1:20;
A=zeros(5,20);
A(1,1:4)=1;
A(2,5:8)=1;
A(3,9:12)=1;
A(4,13:16)=1;
A(5,17:20)=1;
b=ones(5,1);
Aeq=zeros(4,20);
Aeq(1,1:4:20)=1;
Aeq(2,2:4:20)=1;
Aeq(3,3:4:20)=1;
Aeq(4,4:4:20)=1;
beq=ones(4,1);
lb=zeros(20,1);
ub=ones(20,1);
[x,fval]=intlinprog(c,intcon,A,b,Aeq,beq,lb,ub)